//https://leetcode.cn/problems/remove-all-adjacent-duplicates-in-string/

class Solution {
public:
    string removeDuplicates(string s) {
        string ret;
        for (auto ch : s)
        {
            if (ret.size() && ch == ret.back())
                ret.pop_back();
            else
                ret += ch;
        }

        return ret;

    }
};